// JavaScript Document
// stores the reference to the XMLHttpRequest object 
var xmlHttp = createXmlHttpRequestObject();  
 
// retrieves the XMLHttpRequest object 
function createXmlHttpRequestObject()  
{  
  // will store the reference to the XMLHttpRequest object 
  var xmlHttp; 
  // if running Internet Explorer 
  if(window.ActiveXObject) 
  { 
    try 
    { 
      xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
    } 
    catch (e)  
    { 
      xmlHttp = false; 
    } 
  } 
  // if running Mozilla or other browsers 
  else 
  { 
    try  
    { 
      xmlHttp = new XMLHttpRequest(); 
    } 
    catch (e)  
    { 
      xmlHttp = false; 
    } 
  } 
  // return the created object or display an error message 
  if (!xmlHttp) 
      alert("Error creating the XMLHttpRequest object."); 
  else  
    return xmlHttp; 
} 
 
// make asynchronous HTTP request using the XMLHttpRequest object  
function process() 
{ 
  // proceed only if the xmlHttp object isn't busy 
  if (xmlHttp.readyState == 4 || xmlHttp.readyState == 0) 
  { 
    // retrieve the name typed by the user on the form 
    name = encodeURIComponent(document.getElementById("myName").value); 
    // execute the quickstart.php page from the server 
    xmlHttp.open("GET", "quickstart.php?name=" + name, true);   
    // define the method to handle server responses 
    xmlHttp.onreadystatechange = handleServerResponse; 
    // make the server request 
    xmlHttp.send(null); 
  } 
  else 
    // if the connection is busy, try again after one second   
    setTimeout('process()', 1000); 
} 
 
// executed automatically when a message is received from the server 
function handleServerResponse()  
{ 
  // move forward only if the transaction has completed 
  if (xmlHttp.readyState == 4)  
  { 
    // status of 200 indicates the transaction completed successfully 
    if (xmlHttp.status == 200)  
    { 
      // extract the XML retrieved from the server 
      xmlResponse = xmlHttp.responseXML; 
      // obtain the document element (the root element) of the XML structure 
      xmlDocumentElement = xmlResponse.documentElement; 
      // get the text message, which is in the first child of 
      // the the document element 
      helloMessage = xmlDocumentElement.firstChild.data; 
      // update the client display using the data received from the server 
      document.getElementById("divMessage").innerHTML =  
                                            '<i>' + helloMessage + '</i>'; 
      // restart sequence 
      setTimeout('process()', 1000); 
    }  
    // a HTTP status different than 200 signals an error 
    else  
    { 
      alert("There was a problem accessing the server: " + 
xmlHttp.statusText); 
    } 
  } 
} 